1. AMQP, Erlang, and RabbitMQ
OOI Cyberinfrastructure Design Meeting
San Diego, 17th-19th October 2007
Matthias Radestock
October 18, 2007

2. So you want to build a computing infrastructure for ocean observation …
…that transfers, routes, transforms, processes and stores a variety of data streams, and
works, so it needs to be
evolves, so it needs to be
distributed
reliable & resilient
manageable
secure
scaleable
portable
pluggable
interoperable
… like an enterprise messaging system!
October 18, 2007

3. AMQP aims to become THE standard for enterprise messaging
Everyone uses without thinking, so then why is universal commercial business messaging so hard?
→ need an Open Standard Protocol for Message Oriented Middleware
AMQP aims to become THE standard for enterprise messaging
Made to satisfy real needs:
created by users and technologists working together
in development for 3+ years, went public on June 20th 2006
“business dialtone”
October 18, 2007

4. AMQP’s place in the “stack”
Product
Layer
Use
Standard
User Applications
bank
CDL-BPM-CEP
treasury
ESB / SOA / EDA
settlement
WS-*
“Document Model”
reports
FpML
WCF
“Rich Object Model”
positions
Transaction participant
trades
FIX, FAST MQ
Store & forward
orders
JMS
AMQP
Guaranteed Delivery
send/ack
AMQP
Tibco
Content based routing
(1-Many, 1-1)
ticks
Utility Services
e.g. exchange
access links
Cisco
Network
(TCP/IP, UDP, SCTP)
data
October 18, 2007

5. Comparison with some other protocols
SMTP – unreliable, slow
HTTP – synchronous, unreliable, no routing
XMPP – no delivery fidelity or queue management
FTP – point to point, transient, does not work well with NAT/SSL
MQ – exactly once
TCP – at least once, reliable but short lived, no app level state mgmt
UDP – fast but has no delivery guarantees
AMQP - can do all of the above as ‘use cases’
… and switch between them
October 18, 2007

6. How does it work?
Queue
File Transfer
Exchange
Queue
Messaging
Queue
Bindings
Transactions
any language (C, C++, Java, C#, Python, Javascript, Erlang, Lisp, Ruby, Tcl, PHP, …)
any model (native, JMS, Mule, WCF, …)
any payload (binary, XML, SOAP, JSON, …)
any transport (TCP, SCTP, HTTP, …)
any platform (desktop, router, mobile, EC2, …)
reliable
interoperable
manageable
performant
scaleable
October 18, 2007

7. A typical AMQP client program
# Addresses where a particular broker is reachable.
endpoints = [amqp.Endpoint('hostname', 5672),
amqp.Endpoint('alternate', 5673)]
# Construct a session.
session = amqp.Session("1234", 600, endpoints)
# Set up some resources on the broker.
session.ExchangeDeclare("xname",amqp.ExchangeTypes.DIRECT)
session.QueueDeclare("qname") session.QueueBind("xname","qname","routingkey")
# Publish a message.
session.MessageTransfer("xname","routingkey","body")
# Set up a consumer.
session.MessageConsume("qname",MyConsumer(session))
class MyConsumer:
def __init__(self,session):
self.session = session
def handle_MessageTransfer(self,destination,exchange,
routingkey,body):
print "Received message: " + body
return amqp.Constants.ACCEPT
October 18, 2007

8. Under the covers – AMQP Layering
Application
queues, exchanges, messages, transactions, …
API calls
Model
command segmentation / assembly, ordering and acknowledgement
commands
Execution
frameset sequencing frameset (dis)assembly frame flow control reliability (exactly once) and failover
framesets
Session
frames
Framing
(de)multiplexing by channel/stream
heartbeating
framing, integrity check
bytes / packets
Transport
October 18, 2007

9. Communication between peers
messages
Application
Application
Model
commands
Model
controls
Execution
Execution
control frames
Session
Session
control frames
Framing
Framing
Transport
October 18, 2007

10. Under the covers: session reattachment
October 18, 2007

11. AMQP - Inclusive Governance
Protocol
Products
JPMorgan
D/Borse
Credit Suisse
Goldman Sachs
TWIST
Novell
29West
Envoy
Apache
Community Feedback
iMatix OpenAMQ
Red Hat Enterprise Messaging
Iona Celtix AM
RabbitMQ
Cisco Network
AMQP Working Group controls the standard
Diverse products implement the standard
October 18, 2007

12. So you want to build a computing infrastructure for ocean observation …
…that transfers, routes, transforms, processes and stores a variety of data streams, and
works, so it needs to be
evolves, so it needs to be
distributed
reliable & resilient
manageable
secure
scaleable
portable
pluggable
interoperable
… like a telecommunications system!
October 18, 2007

13. No language was well suited for telecom systems development
Erlang History
2007: A New Book!
1996:
Open Telecom
Platform
No language was well suited for telecom systems development
1998:
Open Source
Erlang
1994:
First Product
1993:
Distributed
Erlang
1987:
Early Erlang
Prototype projects
1993:
The First
Book
1984:
Ericsson
Computer
Science Lab
formed
1991:
First fast
implementation
October 18, 2007

14. Erlang Highlights Functional Concurrent Soft real-time Robust
High abstraction level
Concise readable programs
No mutable state
Functional
Concurrent
Soft real-time
Robust
Distributed
Hot code loading
External interfaces
Portable
October 18, 2007

15. Light-weight processes
Erlang Highlights
Functional
Concurrent
Soft real-time
Robust
Distributed
Hot code loading
External interfaces
Portable
Light-weight processes
Highly scalable
Message Passing
October 18, 2007

16. Erlang Highlights: Concurrency
Processes communicate by asynchronous
message passing
receive
{start} -> ………
{stop} -> ………
{data,X,Y} -> ………
end
Pid ! {data,12,13}
October 18, 2007

17. Per-process garbage collection
Erlang Highlights
Functional
Concurrent
Soft real-time
Robust
Distributed
Hot code loading
External interfaces
Portable
Response times in the
low milliseconds
Per-process garbage collection
October 18, 2007

18. Erlang Highlights Functional Concurrent Soft real-time Robust
Distributed
Hot code loading
External interfaces
Portable
Simple and consistent
error recovery
Supervision hierarchies
"Program for the correct case"
October 18, 2007

19. Erlang Highlights: Robustness
Cooperating processes may be linked together
October 18, 2007

20. Erlang Highlights: Robustness
When a process terminates, an exit signal is sent to all linked processes
… and the termination is propagated
October 18, 2007

21. Erlang Highlights: Robustness
Exit signals can be trapped and received as messages
receive
{‘EXIT’,Pid,...} -> ...
end
October 18, 2007

22. Erlang Highlights: Robustness
Robust systems can be built by layering
“Supervisors”
“Workers”
October 18, 2007

23. Explicit or transparent
Erlang Highlights
Functional
Concurrent
Soft real-time
Robust
Distributed
Hot code loading
External interfaces
Portable
Explicit or transparent
distribution
Network-aware
runtime system
October 18, 2007

24. Erlang Highlights: Distribution
B ! Msg
C ! Msg
Erlang Run-Time System
Erlang Run-Time System
network
October 18, 2007

25. Erlang Highlights: Distribution
Simple Remote Procedure Call
{rex, Node} ! {self(), {apply, M, F, A}},
receive
{rex, Node, What} -> What
end
loop() ->
receive
{From, {apply, M, F, A}} ->
Answer = apply(M, F, A),
From ! {rex, node(), Answer}
loop()
end.
October 18, 2007

26. Enables non-stop operation
Erlang Highlights
Easily change code in a
running system
Enables non-stop operation
Simplifies testing
Functional
Concurrent
Soft real-time
Robust
Distributed
Hot code loading
External interfaces
Portable
October 18, 2007

27. Erlang Highlights Functional Concurrent Soft real-time Robust
Distributed
Hot code loading
External interfaces
Portable
"Ports" to the outside world
behave as Erlang processes
October 18, 2007

28. Erlang Highlights: External Interfaces
process
Port
Port ! {self(), {command, [1,2,3]}}, receive {Port, {data, Info}} -> ... end
October 18, 2007

29. Erlang Highlights Functional Concurrent Soft real-time Robust
Distributed
Hot code loading
External interfaces
Portable
Erlang runs on a Virtual Machine ported to UNIX,
Windows, VxWorks, OS X, …
Supports heterogeneous
networks.
October 18, 2007

30. T O P Open Telecom Platform Applications, Libraries & Tools
System Design
Principles O P T
October 18, 2007

31. October 18, 2007

32. Credits
Alexis Richardson, CohesiveFT – for providing much of the AMQP material
Francesco Cesarini, Erlang Consulting – for providing much of the Erlang material
Tony Garnock-Jones, LShift – for the sample code
Matthew Arrott – for inviting me
Thank you!
October 18, 2007

33. Backup slides
October 18, 2007

34. AMQP features In some ways like email but:
What goes in must come out
Very fast - think big - global scale communication
In some ways like TCP and HTTP, but delivers true MESSAGING
Routing and addressing - “buy.ibm.100”
Guaranteed Delivery
Delegation - the concept of a middleman → security, reliability, translation, …
October 18, 2007

35. AMQP version history and roadmap
0-8
routing
Q4’06
0-9
clarifications & bug fixes, experimental work-in-progress extensions
Q4’07
0-10
guaranteed delivery, transport independence, general tidying up
Q1’08
0-11
management, security, federation, addressing
Q2’08
1-0
release
October 18, 2007

36. Under the covers: session creation
October 18, 2007

37. Under the covers: configuration
October 18, 2007

38. Under the covers: message transfer
October 18, 2007

39. Mule binding
<mule-configuration id="RabbitMQ_Demo" version="1.0">
<model name="rabbitmqDemo">
<mule-descriptor name="Mulebot“
implementation="com.rabbitmq.examples.muledemo.Mulebot">
<inbound-router>
<endpoint address="amqp://localhost/?vhost=/&realm=/data&
exchange=chat&exchange-type=fanout&routing-key="/>
</inbound-router>
<outbound-router matchAll="true">
<router className="org.mule.routing.outbound.OutboundPassThroughRouter">
</router>
</outbound-router>
</mule-descriptor>
</model>
</mule-configuration>
October 18, 2007

40. WCF binding service = new ServiceHost(typeof(Calculator),
new Uri("soap.amq://dev.rabbitmq.com:5672/"));
service.AddServiceEndpoint(typeof(ICalculator),
new RabbitMQDualBinding(), "Calculator");
service.Open();
fac = new ChannelFactory<ICalculator>(
new RabbitMQDualBinding() {
ClientBaseAddress =
new Uri("soap.amq://dev.rabbitmq.com:5672/")},
"soap.amq://dev.rabbitmq.com:5672/Calculator");
fac.Open();
calc = fac.CreateChannel();
Console.WriteLine("{0} + {1} = {2}", x, y, calc.Add(3, 4));
((IChannel)calc).Close();
service.Close();
October 18, 2007

41. Erlang Highlights: High-level Constructs
Parsing an IP Datagram using the Bit Syntax
-define(IP_VERSION, 4).
-define(IP_MIN_HDR_LEN, 5).
…… DgramSize = size(Dgram),
<<?IP_VERSION:4, HLen:4, SrvcType:8, TotLen:16, ID:16, Flgs:3, FragOff:13, TTL:8, Proto:8, HdrChkSum:16, SrcIP:32, DestIP:32, Body/binary>> = Dgram, if
(HLen >= 5) and (4*HLen =< DgramSize) ->
OptsLen = 4*(HLen - ?IP_MIN_HDR_LEN),
<<Opts:OptsLen/binary, Data/binary>> = Body,
…..
end.
October 18, 2007